Helix. Helix stainless steel folding ruler.
From the Manufacturer
Folding ruler folds in half to fit into any tool box or pencil pouch. Engineered hinge allows straight, non-kink lines. Easy-to-read markings on the ruler are printed using an printing process instead of acid etching. Imperial markings are in 1/16″ increments, and metric markings are in millimeters. 12″ (30cm) ruler is made of stainless steel and features a cork backing for nonslip grip.